| Hydraulic hoister is the machine which actuates winding by hydraulic motor directly or through transmission, so as to promotion the weight or persons, its basic conditions includes weight promote(down) with reduction velocity, accelerated velocity, constant speed, normal braking and emergency braking. The nature nonlinear,big inertia and time lag is the significant characteristics of electro-hydraulic proportional system of Hydraulic hoister.Hydraulic hoister mainly exist the following problems to further improve :collaborative problem between hydraulic hoister drive system and brake system, the movement precision of Hydraulic motor influents flat layer precision of hydraulic hoister, the comfort feeling of hydraulic hoister and on-line detection system for fault is absent or poor old, etc.In this paper, the main studying is collaborative problem between hydraulic hoister drive system and brake system and the characteristics of hoister drive system control performance. It has summarized function and construction of the hydraulic hoister at the first chapter of this article, and then check and review the development course of hydraulic hoister at inland and abroad, also summarized some problems of hydraulic hoister needed to be further solved, and proved the necessity of the selected topic. Finally, the research contents are summarized and prospected. At the front part of the second chapter it describes structure and working principle of the traditional hydraulic hoist hydraulic system, and then reconstructs it to be electro-hydraulic proportional system. With the third chapter, mathematical model of hydraulic hoister's electro-hydraulic proportional system is established, including model of main circuit that is the speed controlling circuit with pump controlling motor through volume controlling, mathematical model of hydraulic circuit of mechanism for changing flow,at this part of the circuit independent metering technique is introduced for the hydraulic cylinder's controlling, mathematical model of braking system whose throttle valve is replaced by speed regulating valve for more accuracy braking speed.On this basis, the fourth chapter model of hydraulic hoister driving system and braking system is established with AMESim for chasing the influence factors is the two systems' coordination work. In the fifth chapter controlling diagram of speed is established with Matlab/SIMulink, in this section driving system is used of PID and fuzzy PID controlling. Run simulation and compare fuzzy PID to conventional PID,chasing improved speed controlling performance of hoister's electro-hydraulic proportional speed controlling system. |
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